Temperature responsive gauge



H. SEEGERS EI'AL TEMPERATURE RESPONSIVE GAUGE Filed Mayl, 19:59

Patented Dec.fl'6, 1941* UNITED STATES PAT NT. ori-"Ica Hans Seegers and Reyno Ill., assignors to Jas P. Marsh Corporation,

Chicago, lll., a corporation of Dlinois Application May l, 1939, Serial No. 270,988

-Claiina 'I'his invention relates to gauges andmore particularly to a combined temperature and pressure-altitude gauge in which the temperature, altitude, and pressure may each visibly be indicated. Y v

The gauge is preferably provided with a mechanism -of the Bourdon tube type or other suitable pressure element for indicating pressure and altitude and a mechanism of the bimetallic= tem- A further object is to provide an inexpensive and rugged gauge wherein all operating mechanisms are directly supportedby.:hebottom-com#l nection nipple'itselff whereby they will not easily get out of order, and in which the complete assembly comprises a minimum vnumber of parts arranged to easily be assembled. I

Further objects lwill be apparent from the specification and the appended claims.

In the drawing:

Fig. l is a transverse vertical sectional View. through the gauge and nipple with various elementsshmin full lines for purposes ofillustration.

Fig. 2 is a front elevation of the nipple and gauge mechanism shown in EigJmizith-the cas-` ing,dial, and-pointers removed and a' portion of the bracket which forms a bearing for the temperature indicator shaft brokenV away to more clearly illustrate detalls of the transmission.

Referring tothe drawing in detail, the em` bodiment illustrated comprises a nipple I, on

which all of the various mechanisms including` perature responsive type for indicating temperay the dial and ,casing may be mounted and by ture. The latter may be entirely enclosed withwhich they are supported when the gauge is in in the supporting nipple of the gauge and the use. The nipple l is vertically positioned as former marbefse'cured to and supported on the shown with respect to theA gauge casing and is nipple, which is threaded or otherwise constructpreferably an elongated casting having a threaded in a manner to be inserted in or otherwise se- 15 ed portion 2v adapted for insertion in a complecured in operative relation to theusual complementary threaded opening in a boiler or tank., mentary opening ina-reservoir ortank. lwhereby the gauge may be vertically supported.

, This invention is an improvement over, or a The nipple I is provided with laterally extending modification of, our prior application Serial No. anges 3 (Fig. 2) and is adapted to extend 239,906, filed November 12, 1938, and is particuthrough the bottom wall of the casing 4, as larly directed to a gauge structure of the type shown in Fig. l, whereby the flanges 3 are adtherein described in which the gauge isprovided jacent the back of the casing and the casing with a bottom connection and in which a special may then be secured to the flanges 3 by means type of I. transmission is provided between the of suitable screws inserted into the threaded shaft of the b imetallic element and the temperopenings in the flanges. The casingis' thereby ature pointer or indicator, whicltransmission rigidlxfsupported on the nipple in the position enables contraction and expansion of said ele- ShOWn in Fig. l. 'I'he front of the casing is open ment or longitudinal movement of said shaft and is provided with a bezel 6 secured by means while maintaining at all times accurate regis of screws or other suitable fastenings and artration of,the pointer. 'llhessaid prior applica- 30 ranged to retain a glass window 1, as shown.

tionazoversabazk connection type gauge and the The nipple I is provided With a longitudinal present application particularly relates to a botchamber having a tubular extension or housing tom connecto'type of gauge, and the said prior 9 inserted inthe outer end thereof and soldered application may be referred to for a better un- 0r brazed 0I' Otherwise Sealed in the nipple. The derstanding of our present invention. housing S is closed at its outer end by-means of a plug I@ sealed therein, whereby the nipple and extensionform a rigid housing for a suitable emperature responsive mechanism.f The upper endof the plug It is reduced in diameter and al 40 helical bimetallic temperature responsive element I'I of a typewell known in the art is secured to Hthe reduced end of the l'plug by any suitable means. The opposite end of the bimetallic element II is secured to a longitudinal shaft I2 which is rotatably supported at its lower end in a bearing I3 in the plug Il)v and, adjacent itsupper end, is supported in a suitable bearing portion I4 of the nipple.

A dial I5 is supported on the nipple by means shown in Fig. 2. These screws bracket I8, which forms the outer bearing of a horizontal indicator shaft I9, this shaft of screws I6 secured in the threaded openings I'Il also support, aV

the inner end of- |9 being providedwith a suitable bearlili ing at in the body of thenipple. An indicator l A provide a suitable tion of the crown gear.

needle 2l is secured to the outer end of the shaft I3 by any suitable means so that it may be moved over a temperature indicating scale on the dial I5. The dial I5 and the scales and associated indicating needles of the present embodiment may be substantially identical with those illustrated in the previously mentioned copending apterfere with accurate registration of the needle in accordance with temperature variations. However, in the vertical or bottom connection type of gauge of the instant disclosure, the indicator shaft I9 is at a right angle to the thermometer shaft I2. Therefore, if' any ordinary type of transmission, such as bevel gears, is used between these shafts, lost motion 'or other objectionable features interfere with correct reading.

In the present embodiment and in order to positive transmission between the thermometer shaft and the needle, a special type and arrangement of crown gears 22 and 22a has been provided. The gear 22 is secured to the upper end of the vertical shaft I2 and the companion gear 22a is securedto the inne!` end of the indicator shaft I9 so that its inwardly extending teeth are in mesh with the downwardly extending elongated teeth of the gear 22. These gears are preferably formed of sheet metal, as shown in Figs. 3, 4, and 5, and are provided with laterally 'extending elongated teeth 23. The gears are preferably first blanked in a substantially star-shaped form such as shown in Fig. 5 and by dotted lines in Fig. 4. The elongated teeth are then formed at right angles to the body of the gear blank substantially on the dotted line shown in Fig. 5, whereby an arcuate portion 24 of the space between the teeth extends into the flat porcorresponds in' width to the space between the teeth after they are tion shown in Fig. rounded end s, whereby, when the ends of the teeth on the indicator gear are meshed with the -teeth of the crown gear on the vertical shaft I2,

a very smoothly operating transmission is pro- I vided substantially without lost motion or backlash.

ItV will'be apparent that, when the gears are meshed in the manner shown, the indicator needie 2| will be positively operated in accordance with the rotation of tne vertical shaft I2 irrespective of any Ilongitudinal movement of the vertical shaft due to expansion and contraction of tne bimetallic element. As the space between -tne teeth is uniform and the teeth mesh accurately, the raising or lowering of the gear on the vertical shaft nas no effect on the needle setting and the position of the needle is, therefore, only influencedby rotative movement.

A pressure responsive element preferably in the form of a Bourdon tube 25 is provided and the open end thereof is secured in the side of the nipple I in the usual manner, as illustrated particularly inFig. 2. This open end of the Bourdon tube communicates through a horizontal restrict- This arcuate opening formed laterally to the posi- 4. The teeth are made with ed passage `26 with a'vertical restricted passage 2`I extending' longitudinally of the nipple and terminating outside the housing 9 and, therefore, inside of the tank, on which the gauge may be mounted. By this means, pressure in the tank will be transmitted to the Bourdon tube` in the most effective manner.

The .closed end of the Bourdon tube is secured to a pressure indicating mechanism 28 and this mechanism is secured to an upwardly extending bracket 29, which is, in turn, mounted on the nipple I by means of screws 30. The indicating mechanism is provided with the usual forwardly extending rotatable shaft 3|, which extends through the dial I5 andon which is mounted a needle or pointer 32 which moves over suitable graduations on thedial for indicating altitude and other graduationsfor indicating pressure.

An arm 33 is secured to the shaft 3 I immediately behind the dial I5 and arranged to operate a maximum pressure registering pointer 34 which is mounted on a bearing on the dial and is coaxial with the shaft 3l. This pointer or so-called telltale is frictionally retained on its bearing, whereby it will be retained in the maximum indicating position to which it is moved by the arm 33 during the operation of the device. The rear of the dial may be provided with pressure indicating graduations over which the telltale `needle 33 passes when it is moved by the arm 33.

An auxiliary needle 35 may be frictionally mounted axially with the shaft 3I and arranged to manually be moved over the outside of the dial to any desired position on the altitude and pressure gauges. This needle is preferably of red or some contrasting color and is intended to be set manually' to indicate any altitude or pressure which it is desired to approximately maintain. The various needles and their arrangements just described may be substantially identical with those shown in the previously mentioned copending application.

The free end of the Bourdon tube 25 is provided with a short outwardly extending arm 36. This arm is pivoted to the end of .the Bourdon tube by means of a pivot screw 3l, by which the arm may be located in-xed position with respect to the end of the tube 25. A lock washer 38 is provided between the arm 36 and the end of the Bourdon tube, so that the arm may rigidly be secured in any. acLiusted position. The arm 36 is connected to a pivoted arm 39, which forms an operating part of the needle mechanism 28, by means of a link 40. By loosening the screw 31, the arm 36 may be adjusted to any desired position to thereby adjust the` pressure and -altitude indicating needle 32 to any desired position relative to the scale with which it co-operates.V

These gauges are sometimes subjected to very rough handling, particularly during shipment. A stop 4I is, therefore, provided which is preferably somewhat resilient and is in the form of a U-shape'd arm having its free, end positioned above the shaft I2 and gear 22 thereon so as to limit the upward movement thereof, whereby the gears 22 and 22a are always retained in mesh irrespective of any rough handling or shaking of the gauge. As shown in Fig. 1, end clearance is provided in the bearing I3 so that the shaft is free to iioat longitudinally in response to any longitudinal expansion or contraction of the element I4 which may take, place throughout the normal indicator range.

Modifications may be made without departing from the spirit of the invention, and it is thereclaimed and desired to be secured by Letters- Patent is: l. In a temperature responsive gauge of the vcharacter described, the combination with an elongated nipple for attachment to an opening in a tank and having a thin walled tubular extension forming a housing extending into the tank and closed at its outer end, a longitudinal shaft having a bearing in the outer end of said housing and a bearing adjacent the outer end of said nipple and mounted for free rotary and longitudinal movement, and a helically wound bimetallic temperature responsive element hav,- ing one end secured to the outer end of said housing and vthe other end secured to said shaft to rotate said shaft in vresponse to temperature changes and enable saidshaft to float longitudinally in accordance with variation in the length of said element, of a pointer rotatable in a plane parallel with the longitudinal axis of said shaft. a pair of crown gears rigidly secured respectively to said shaft and said pointer to cause positive movement of said pointer in accordance with rotary movement of said shaft and to enable simultaneous independent longitudinal movement of said shaft.

2. In a gauge, a housing, a supporting nipple extending from said housingand having a reduced extension forming a casing adapted to extend into a variable-temperature chamber, a longitudinal shaft extending through said nipple and into said housing and mounted for free rotary and longitudinal movement, a helically wound bimetallic thermally responsive element in said casing and having one end secured thereto and the opposite end secured to said shaft and arranged to rotate said shaft and move said shaft longitudinally in response to temperature changes, a gear axially secured to said shaft adjacent the end thereof in said housing, said gear Y having teeth parallel with said axis and materially longer from end to'end than the longitudinal movement of said shaft under normal working temperature conditions. a crown gear having its axis substantially at a right angle to the axis of said shaft and meshing with said shaft gear in'a manner to substantially prevent excessive lost motion therebetween irrespective of the longitudinal position of said shaft gear, and

an indicator operated by said crown gear only in response to rotary movement of said shaft.

3. A temperature gauge comprising a nipple for mounting in a gauge housing to project vertically therefrom, said nipple comprising a body portion having a vertical shaft passage there-` through and lincluding a thin-walled extension from the outer end of said body portion to form a housing for a temperature responsive element, a vertical shaft in said housing and nipple body and having a bearing adjacent; the outer end of said housing and another Ibearing in the upper portion of said nipple, said shaft being mounted for -free rotary movement and oating longitudinal movement in said bearings. a helically wound, temperature-responsive. expansibie element in said housing andhaving one end secured to said shaft and the other end secured to said extension so as to rotate said shaft in response to variations. in temperature and also enable free floating axial movement of said shaft in response to longitudinal expansion and contraction of said f element, a horizontal shaft rotatably mounted on the upper end of said nipple and in the axial plane of said vertical shaft and having a crown gear rigidly secured thereon, a wide-face gear rigidly secured on said vertical shaft and in vertically sliding mesh with-said crown gear, and an indicator on said horizontal shaft.

4. A claim according to claim 3 characterized by said wide face gear being positioned above said horizontal shaft and in mesh with the topl of said crown gear. i

5. A claim accordingto claim 3 characterized by said wide face gear being positioned above said horizontal shaft and in mesh with the top of said-crown gear and a forwardly extending bracket on said body portion and extending over said vertical passage and forming bearings for both of said shafts.

HANS SEEGERS. REYNOLD T. HEDFIELD. 

